Cold start cooking system

ABSTRACT

A control system for a cooking appliance enables a consumer to perform a complete cooking operation regardless of whether food is placed into an oven after a preheating operation or from a cold start. In general, under circumstances wherein the consumer does not intend to allow the oven to be properly preheated prior to inserting the food to be cooked therein, an initial programming operation is followed by an additional control sequence by the user to establish a cold start cooking operation wherein the lack of preheating is automatically compensated for, preferably by causing the oven to reach a peak temperature for the oven which is well above a temperature set by the user for the overall cooking operation. After the peak temperature is reached, the oven temperature is allowed to gradually reduce to the preprogrammed cooking temperature.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention pertains to the art of cooking and, moreparticularly, to a control system for a cooking appliance which enablesthe appliance to be selectively operated in a cold start cooking mode.

[0003] 2. Discussion of the Prior Art

[0004] Conventional cooking appliances generally perform cookingoperations through radiant heat developed from bake and/or broil heatingelements. Such types of cooking appliances can take various forms,mainly ranges and wall ovens. When utilizing a conventional cookingappliance, the oven is initially controlled to proceed through a preheatcycle in order to establish a desired cooking temperature. Oftentimes, asignal is provided to a user when the preheat cycle is complete in orderto indicate when the food to be cooked can be placed in the oven. Insome cases, both the bake and the broil elements are actuated during thepreheat cycle. In addition, it is also known to incorporate an internalfan in an oven for more evenly distributing developed heat. Convectionsystems are actually quite prevalent in microwave and other types ofovens which do not require preheating. However, utilizing convectionsystems in cooking appliances employing bake and broil elements is alsoknown.

[0005] Regardless of the type of overall heating system utilized, it isnot uncommon for a consumer to place food into an oven for apredetermined cook time without first enabling the oven to reach apreheat temperature. Since cooking times set forth in recipes or othercooking instructions are established based on an oven being preheated,failure to preheat the oven directly affects the overall foodpreparation. Under such circumstances, the user must either mentallydetermine a supplemental cooking time period for the food item or, ifthe cook time is not altered, the food will be at least slightlyundercooked.

[0006] Based on the above, there exists a need in the art for a systemwhich will enable a consumer to readily alter an established cookingoperation when it is known that an oven is not going to be allowed toreach a preheat temperature prior to placing food in the oven. In otherwords, under conditions wherein a cold start cooking operation is to beperformed, it would be beneficial to enable the consumer to easily altera programmed cooking operation to automatically compensate for the lackof a preheat cycle.

SUMMARY OF THE INVENTION

[0007] The present invention is directed to a control system for acooking appliance which enables a consumer to perform a complete cookingoperation regardless of whether food is placed into an oven after apreheating operation or from a cold start. In general, the inventionenables a consumer to program a cooking appliance through a controlpanel in a conventional manner based on established cooking times andtemperatures in accordance with recipes or other cooking instructions.However, under circumstances wherein the consumer does not intend toallow the oven to be properly preheated prior to inserting the food tobe cooked therein, an additional control sequence can be performed bythe user, such as the selection of a cold start feature. Thereafter, thecontrol system for the cooking appliance will automatically alter theoverall cooking operation to compensate for the lack of a preheat stage.

[0008] In accordance with the most preferred form of the invention, anadditional button is provided on a programming pad of the control panelfor the cooking appliance, wherein the consumer need only press theadditional button when a cold start cooking operation is to be employed.In one embodiment, when a cold start cooking operation is selected, thecontrol system of the cooking appliance establishes a peak temperaturefor the oven which is well above a temperature set by the user for theoverall cooking operation. After the peak temperature is reached, theoven temperature is allowed to gradually reduce, with a lattermostportion of the established cooking time actually operating the oven atthe preprogrammed cooking temperature.

[0009] Additional objects, features and advantages of the presentinvention will become more readily apparent from the following detaileddescription of a preferred embodiment when taken in conjunction with thedrawings wherein like reference numerals refer to corresponding parts inthe several views.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a partial perspective view of an electric rangeincorporating a cold start cooking system according to the invention;

[0011]FIG. 2 is a front view of a control panel, forming part of therange shown in FIG. 1, including a schematic illustration of a controlarrangement that forms part of the cold start cooking system; and

[0012]FIG. 3 is a graphical representation of the temperature of theoven cavity when heated in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] With initial reference to FIG. 1, the invention is illustratedfor use in connection with an electric range, generally indicated at 2.In the embodiment shown, electric range 2 includes a cabinet 5 withinwhich is arranged an oven cavity 8 having an associated lower heatingelement 9 and a door 10, shown in an open condition wherein access tooven cavity 8 is permitted. The following description assumes thatheating element 9 is of a conventional electric heating element design,but it is considered within the scope of this invention that heatingelement 9 may be a gas heating element or of any other conventionaldesign. This figure also illustrates the presence of a viewing window 11in door 10. Furthermore, within oven cavity 8, a fan 12 and an upper,broil heating element, a part of which is shown at 14, are provided. Ina manner known in the art, cabinet 5 is provided with a light switch 16which functions to turn on a light (not shown in FIG. 1 but indicated at17 in FIG. 2) to illuminate oven cavity 8 upon the opening of door 10.

[0014] Cabinet 5 is also provided with an associated range top 18 whichsupports various spaced surface heating elements 20-23 in a manner knownin the art. At an upper rear portion, cabinet 5 is provided with acontrol panel 28. Control panel 28 includes a plurality of knobs 36-39for use in selectively activating and deactivating surface heatingelements 20-23 respectively. In addition, control panel 28 is shown toinclude a central display 44, such as an LED or LCD display unit (alsosee FIG. 2). Furthermore, control panel 28 is provided with a numberpad, generally indicated at 46, having buttons for the numbers zero (0)through nine (9), with the zero (0) button also functioning as a resetcontrol button.

[0015] Although the particular features incorporated into electric range2 could vary greatly within the scope of the present invention, for thesake of completeness in describing a preferred form of the invention,control panel 28 of range 2 is also shown to include a lower row ofcontrol buttons, generally indicated at 48, which are provided to selectvarious operational modes for range 2. For instance, the row of controlbuttons 48 can be used to select bake, broil and clean modes for range 2through respective buttons 49-51. In the particular embodiment shown, anadditional convection baking mode, which is essentially defined by abaking mode with the further activation of fan 12, can also be selectedthrough button 53.

[0016] In another form of the invention, the user may program theoperation of range 2 through the use of the lower row of control buttons48, control button 53 and numeric pad 46, as well as timer buttons 62and 63. Furthermore, buttons 66 and 67 are provided to enable a consumerto set desired countdown and clock times, in combination with numericpad 46, respectively. Button 68 performs a stop or clear controlfunction, while button 69 enables a consumer to turn on light 17 withoutopening door 10 such that oven cavity 8 can be selectively viewedthrough window 11. Button 70 is provided to initiate the cold startfunction in accordance with this invention as will be described below.Finally, an Auto Set button 72 is provided and can be used to performvarious programming functions as will also be discussed below. Ofcourse, although various buttons are described for use on control panel28, other types of control members, including a wide range of switches,could equally be employed. In addition, although the invention is beingdescribed with reference to range 2, it should be recognized that theinvention is applicable to various types of cooking appliances,including wall ovens and the like.

[0017]FIG. 2 shows control panel 28 including an associated CPU 75 forcontrolling fan 12 and the heat sources of range 2, i.e., at leastillustrated heating elements 9, 14 and 20-23. CPU 75 also includes coldstart circuit 78 which is activated through button 70 as will be morefully discussed below. The operation of light 17 and heating elements20-23 is performed in a manner known in the art, does not constitutepart of the present invention and therefore will not be discussedfurther here. However, it will be mentioned that Auto Set button 72 canbe used to assist the user in programming a cooking operation for range2. For example, if bake button 49 is selected, the operating temperaturecan be set directly through number pad 46 or by pressing Auto Set button72 once for a certain starting temperature, e.g. 350° F. (177° C.), andsubsequently for adding a set temperature value, e.g. 25° F., upon eachfurther depression of button 72. If a broil operation is selectedthrough button 50, Auto Set button 72 can be used to toggle between “Hi”and “Low” settings for heating element 14. In any event, this operationis known in the art and only provided for the sake of completeness.Instead, the present invention is particularly directed to the manner inwhich CPU 75 is programmed to cause heating of oven cavity 8 upon theselection of the cold start feature by a user through button 70. Moreparticularly, cold start circuit 78 of CPU 75 operates in accordancewith the present invention to assure that a complete cooking operationis performed on a food item placed within oven cavity 8 even though ovencavity 8 is not properly preheated.

[0018] In using range 2, a consumer may select a desired cookingfunction or operational mode through control buttons 49, 50 and 53,while also establishing an operating time period for the respective heatsource utilizing numeric pad 46 and timer buttons 62 and 63. Again,numeric pad 46 or Auto Set button 72 can be used to set certainoperating parameters as well. In one embodiment, the selected operationwill be shown by illuminating key words or symbols in central display44. The preceding description is similar to the structure described inU.S. Pat. No. 6,153,858, the entire disclosure of which is hereinincorporated by reference.

[0019] It is preferable to employ some type of audible or visualindicator to the consumer when certain time periods have expired orcertain temperatures have been reached. This function is performed byincorporating a piezoelectric buzzer or the like as indicated in FIG. 2at 80. For instance, as with a conventional cooking appliance, buzzer 80is preferably used to indicate the end of a cooking operation. Inaddition, when range 2 is used in a more conventional mode wherein ovencavity 8 is permitted to preheat prior to the placing of food thereinfor cooking, buzzer 80 can signal a user at the end of the preheatstage.

[0020] Of course, as indicated above, it is not uncommon for a consumerto place food into an oven for a predetermined cook time without firstenabling the oven to reach a preheat temperature. Since cooking timesset forth in recipes or other cooking instructions are established basedon an oven being preheated, failure to preheat the oven directly affectsthe overall food preparation. However, in accordance with the presentinvention, the user need only press button 70 after programming acooking operation wherein the user is not going to allow oven cavity 8to preheat. Therefore, a signal is sent to CPU 75 that cold startcircuit 78 is to be utilized in connection with the selected cookingoperation. In general, when a cold start mode is selected, an actualcook time is calculated to arrive at an equivalent temperature and cooktime associated with a preheat start. That is, cold start circuit 78incorporates a control algorithm which functions to determine therequired cold start time based on the cook time and temperature set bythe user. This cold start time is then added to the cook time to arriveat an overall cooking operation time.

[0021] As an example, if biscuits are recommended to be cooked at 475°F. for 12 minutes and the cold start selector button 70 is pressed, CPU75 would operate one or more of heat sources 9 and 14, perhaps even withfan 12, in a cold start mode for an extended period of time, such as 15minutes. This additional time would compensate for the user placing thefood in oven cavity 8 and initiating the cooking operation withoutallowing oven cavity 8 to reach its preheat temperature. Ultimately, thetotal cooking time is reduced by eliminating the preheat stage.

[0022] Certainly, there are various ways in which the invention canaccomplish the goal of allowing a user to readily select a cold startcontrol feature, thereby establishing an intelligent, easy and efficientuse of range 2. Of course, the actual preheat time for oven cavity 8will be determined by the food load placed therein. That is, the morefood placed in oven cavity 8, the longer a requisite preheat time.Correspondingly, when a cold start operation is selected, the amount oftime added to the preprogrammed cooking time should effectively varywith the food load. In accordance with the most preferred form of theinvention, the actual time added based on a cold start is establishedbased on an integration of the area under a set temperature and above apreheat curve.

[0023] To this end, FIG. 3 represents a time/temperature curveassociated with the use of oven cavity 8 in cooking a food item for 60minutes at 350° F. That is, the food has already been placed in ovencavity 8 and a cooking operation for 350° F. for 60 minutes has beenprogrammed. Depending on the food load, oven cavity 8 will reach the settemperature in a certain period of time, say 15 minutes. CPU 75, incombination with cold start circuit 78, would then establish a peaktemperature to be reached in oven cavity 8. In the example shown, thispeak or overshoot temperature equals 50° F. above the 350° F., i.e.,400° F. The cooking operation would then proceed to reduce thistemperature down to the programmed temperature over a portion of theoverall cooking operation, with this portion being equal to ¼ or 15minutes in the example provided. The remaining time in the overallcooking operation would be at the programmed 350° F. temperature. Ofcourse, due to the activation/deactivation periods of the heat source(s)9, 14, the actual temperature in oven cavity will fluctuate about thisset temperature as clearly represented in FIG. 3.

[0024] Although described with reference to a preferred embodiment ofthe invention, it should be readily understood that various changesand/or modifications can be made to the invention without departing fromthe spirit thereof. For instance, even though the invention has beendescribed as employing a special button on the control panel for thecooking appliance to establish the cold start cooking sequence, othercontrol arrangements could be equally employed, including the activationof two or more other buttons simultaneously. In addition, although theinvention has been described in connection with an electric cookingappliance, the invention could be employed in a wide range of cookingappliances, including gas and/or convection ovens, including those alsoincorporating microwave or other heat sources. Of course, control panel28 can take various forms and configurations in accordance with theinvention. Furthermore, it should be recognized that the line in FIG. 3only represents a typical temperature progression in accordance with theinvention, and that a variety of other graphs may result. In general,the invention is only intended to be limited by the scope of thefollowing claims.

We claim:
 1. A cooking appliance incorporating a cold start cooking modecomprising: an oven cavity; at least one heating element disposed insidesaid oven cavity; a control panel including a plurality of input membersfor programming at least time and temperature parameters for a cookingoperation within the oven cavity and for selectively establishing a coldstart cooking mode for the cooking appliance; and means for controllingsaid at least one heating element in accordance with a cold startcooking sequence upon establishing the cold start cooking mode, saidcontrolling means being adapted to alter at least one of the time andtemperature parameters programmed for the cooking operation in order tocompensate for a lack of preheating of the oven cavity.
 2. The cookingappliance according to claim 1, wherein the plurality of input membersincludes a selector member dedicated for use in establishing the coldstart cooking mode.
 3. The cooking appliance according to claim 1,wherein the controlling means operates said at least one heating elementso as to initially elevate said oven cavity to a temperature above theprogrammed temperature parameter and then to subsequently reduce theoven cavity towards the programmed temperature parameter.
 4. The cookingappliance according to claim 3, wherein the controlling meansestablishes an actual cook time which is greater than the programmedtime parameter.
 5. The cooking appliance according to claim 1, whereinthe controlling means establishes an actual cook time which is greaterthan the programmed time parameter.
 6. The cooking appliance accordingto claim 5, wherein the controlling means establishes the actual cooktime depending upon a food load placed in the oven cavity for thecooking operation.
 7. The cooking appliance according to claim 1,further comprising: a fan exposed to the oven cavity, wherein saidcontrolling means is further adapted to operate said fan to control atemperature in said oven cavity.
 8. A cooking appliance incorporating acold start cooking mode comprising: an oven cavity; at least one heatingelement disposed inside said oven cavity; a control panel including aplurality of input members for programming at least time and temperatureparameters for a cooking operation within the oven cavity and adedicated cold start selector member; and a controller for operating theat least one heating element in a first mode, wherein the cookingoperation is performed based on the programmed time and temperatureparameters and with preheating of the oven cavity, and a cold startcooking mode, wherein at least one of the programmed time andtemperature parameters is automatically adjusted to alter the cookingoperation in order to compensate for a lack of preheating of the ovencavity, said cold start cooking mode being established upon activationof the cold start selector member.
 9. The cooking appliance according toclaim 8, wherein the controller regulates the at least one heatingelement to initially elevate said oven cavity to a temperature above theprogrammed temperature parameter and then to subsequently reduce theoven cavity towards the programmed temperature parameter in the coldstart cooking mode.
 10. The cooking appliance according to claim 4,wherein the controller establishes an actual cook time which is greaterthan the programmed time parameter when the cold start cooking mode isselected.
 11. The cooking appliance according to claim 8, wherein thecontroller establishes an actual cook time which is greater than theprogrammed time parameter when the cold start cooking mode is selected.12. The cooking appliance according to claim 11, wherein the controllerestablishes the actual cook time depending upon a food load placed inthe oven cavity for the cooking operation.
 13. The cooking applianceaccording to claim 8, further comprising: a fan exposed to the ovencavity, wherein said controller is further adapted to operate said fanto control a temperature in said oven cavity.
 14. In a cooking applianceincluding an oven cavity, at least one heating element disposed insidesaid oven cavity, and a control panel having a plurality of inputmembers for programming a time and temperature parameters for a cookingoperation within the oven cavity, a method of performing the cookingoperation without preheating the oven cavity comprising: A) elevatingsaid oven cavity to a first temperature above the temperature parameterprogrammed for the cooking operation; B) reducing said oven cavity to asecond temperature which is substantially below the first temperature;and C) substantially maintaining the second temperature for a determinedperiod of time.
 15. The method of claim 14, wherein the cookingoperation is performed for an actual cook time which is greater than theprogrammed time parameter.
 16. The method of claim 15, furthercomprising: establishing the actual cook time based upon a food loadplaced in the oven cavity for the cooking operation.
 17. The method ofclaim 14, further comprising: selecting the cooking operation without apreheating of the oven cavity through a dedicated cold start selectormember provided on the control panel.
 18. The method of claim 14,further comprising: operating a fan to distribute air within said ovencavity during at least a portion of the cooking operation.